Slotting machine



1932- H. E. FRENTZEL 1,372,270

SLOTTING MACHINE File d Jx lne 18, 1926 5 Sheets-Sheet 1 INVENTOR BY p ATTORNEY Aug. 16, 1932. H. E. FRENTZEL 9. 3

SLOTTING MACHINE Filed June 18, 1926 5 Sheets-Sheet 2 OR fimwA/v fkmrza BY W ATTORN EY Aug. 16, 1932. H. E. FRENTZEL 1,872,270

SLOTTING MACHINE Filed June 18, 1926 5 Sheets-Sheet 3 ATTORN EY 5 Sheets-Sheet 4 H. E. FRENTZEL SLOTTING MACHIN Filed June 18, 1926 l/I/I/I/l/ Aug. 16, 1932.

ATTORNEY Aug. 16, 1932. H. E. FRENTZEL SLOTTING MACHINE Filed June 18 1926 5 Sheets-Sheet 5 ww k k 5 W g Q 5 fiw Q Q2 QQ m m WHY QLA

P3 INVENTOR fimMA/vZT/kmrza.

TTORNEY Patented Aug. 16, 1932 D. STATESQPATENT Y EI HERMAN n. FR-ENTZEL, or MILWAUKEE, ,wrsoonsm, Assrenon r THE FALK con roiie'rron, or MIL AUKEE, Wisconsin, A CORPORATION 01 WISCONSIN sror'rme' MACHINE Application filed June is, 1926. Serial No. 116,784.

This invention relates to slotting machines and more particularly to machines for forming a series of longitudinally flared slots 1n the periphery of coupling disks and the like.

A machine for this general"purpose is described inmy copending application, Serial No. 91,019, filed February 27, 1926. In that a machine for the purpose mentioned of mechanism for reciprocating the tool or the like, alternately, along two distinct paths,

conforming to .the respective contours of the walls of each slot.

Another object is the provision of means for effecting the ready adjustment of the tool operating mechanism in order to form slots of various widths. I

Another object is the provisionof novel and improved means for feeding thetooltoward and fromthe work. H Another object is the provision of novel and improved means for feeding the tool and indexing the work in definite sequence.

Otherobjects and advantages will appear from the following description of an illustrative embodiment of the present invention. In the drawings Figure 1 is a vertical longitudinal sectional view of a slotting machine constructed in accordance with the present invention.

Fig. 2 is a sectional view taken substantially along the line 2-2 of Figurel. I t

Fig. 3 is a horizontal sectional view taken substantially along the line 33 of Figure 2.v

Fig. 4c is a vertical sectional view taken substantially along the line 44 of Figures 1 and 3.

Fig 5 is a vertical sectional view taken substantially along the line 55 of Fig. 1.

Fig.6 is a detail view of the trip mechanism, on a larger scale, shown in Fig. 1.

Fig. 7 is a view taken substantially along the lines 7?' ofFigure 1.

Figs. 8 and 9are diagrammatic views similar to Fig. 7 illustrating the action of the cutter and cutter operating mechanism.

Fig. 10 is a fragmentary View diagrammatically illustrating the character of the slots produced by this machine.

. The machine selected for illustration is designed to cut-a series of longitudinally flared slots a in the periphery b of a coupling disk 0.

From an inspection of Fig. 10 it will be noted that the opposite side walls a and d of each slot are oppositely curved longitudinally, one wall lying within a curved surface indicated by the line 6 and the other wall lying in a,

curved surface indicated by the line (2. To produce slots of this form, the single cutter of the present machine is caused to recipro cate alternately along paths coincident with these curved surfacese and e.

The coupling element or disk c, as shown in full lines in Figures 1 and 3 and indotted lines in Figure 2, is supported upon an upright housing 10, having a base plate '11 mounted for lengthwise adjustment in horizontal ways 12 formed in the upper forward portion of an appropriate base frame 13. A screw 141, journaled in a cross-bar 15 fixed to the base frame, and threaded through an appropriate block 16 fixed to the plate 11, constitutes a convenient means for adjusting the housing 10 toward and from the cutter 17, so as to accommodate the machine to work of various diameters. The work is fixed in a' well known manner to a vertical shaft 18 extending upwardly therethrough and through the housing 10. This shaft is actuated and controlled by a worm wheel 19 fixed to the lower end thereof and meshing with a worm 20 carried by a horizontal shaft 21, which in turn is connected through a change speed gear train 22 of a well known type, to a horizontalshaft 23. Shafts 21 and 23 and gears 22 are carried by a housing 24 surrounding the worm 20 and worm wheel 19, and supported by'and beneath the base plate 11 of theupright housing 10. The gears 22 are so selected, that for each complete rotation of shaft 23, shaft 18 and consequently the work'is rotated through en angle corresponding to the i desired spacing of the slots in thework.

Shaft 23 is rotated intermittently .byappropriate mechanism such as will now be described.

A shaft 25, 3ournalled 1n fixed bearings 26 and 26 in the base frame 13, is connected in driving relation with the shaft 23, through a hollow shaft 27. Shaft 23 is fixed at one end within this hollow shaft 27, and the end of the other shaft 25 is slidably fitted therein and provided with a key and slot connection 28' therewith. This driving relation is thus maintained in all positions of adjustment of the housing 10. friction clutch of appropriate form tends at all times to rotate the shaft=25 in'one-direc-'- tion, and an intermittently released locking mechanism operates normally to l1oldthis shaft against rotation under the influence of the clutch.

The clutch shown in Figure 1 comprises a disk 29 having hub portions 30 and 31 fixed to th-e shaft 25. The hub portion-31 is provided withan enlarged portion 32 adapted to looselyrecelvea ring 33,-hav1nggear teeth 34;formedon the periphery'thereof. A sec- -ond ring 35,'surrounding the hubportion 31,

is carried by a series of studs 36, projecting from'the face of the enlarged portion so as to rotate therewith. The ring 33 carries a series-0ffriction blocks 37, preferably of -w-ood-,- interposed between the disk 29 and rlnga35, and maintained in contact therewith under the pressure of .a series of springs 38, each interposed between the ring 35 and a nut 39-on one of the'studs 36. i

The ring 33is driven continuously by a pinion 40, meshingwith the teeth 34 thereon, and the frictional contact between the blocks 37-with the-ring 35 and disk 29 provides a yielding drivefor the shaft 25. The pinion 40'is' fixed to a shaft 41, journalle'd in the.

base frame 13, this shaft being driven'from the-main drive shaft 42 through a pinion 43 and gear 44. The shaft 42 is journalled in the base frame 13 and is drivenby a pulley 45 fixed thereto, the pulley being connected to an'ele'etric motor 46 in the bottom of the base frame through a belt 47.

' The mechanism shown for releasably lockingrthe shaft 25 against rotation comprises a cam 48 fixed to the hub portion 30 and formed with as shoulder 49 for locking engagement with a detent 50 of appropriate form. (See Fig.-

In this instance the detent comprises a-bar, mounted for lengthwise reciprocation in a fixed bracket 51. A spring 52 normally maintains the bar 50 in the advanced locking position of Figure 5, but the bar is intermittently withdrawn from engagement with the shoulder 49 of the cam 48 by mechanism to be hereinafter described, and when so withdrawn the cam and shaft 24 are free to rotate through one complete revolution under the influence of the friction clutch hereinabove described.

A tool carriage 53 in-the form of a hollow A continuously operated.

casting is mounted for lengthwise reciprocation toward and from the work. As indicated in Figures 2, 3 and 4, this carriage is supported by and between a pair of upright side members 55, fixed to the upper rear portion of the base frame 13, and formed with form,-fixed in a vertically reciprocating carrier plate 52. The plate 62-is provided at its opposite sidee'dges wi-th laterally projecting tongues 63,slidably engaged in vertical guides 64 formed in the front end of the-tool car-- riage 53. (See Figs-2 and Appropriate cover plates 65*retainl'the tongues in "the guides. Although the carrier plate 62 is thus retained in a true-vertical plaine,it will be noted from an inspection of F igu-re-3,thatsuflicient clearance is provided to permit lim-- itecl lateral movement of this plate within that plane. The carrier plate is' reciprocatedi by'a pair of links'66and- 67 pivotally connected at their upper ;ends 68 and'69 to the lower endof the late, and connected at their I lower ends to crank pins 7 0' and 71' carried by the forwardends of two crank shafts 72'and 73, respeotively.- The forward portions of the I crank shafts '72 and-73 are jo'urnalle'd int-he lower front wall 74 of the tool carriage, and the rear ends-thereof -are journalle'd in a transverse .rail 75 fixed' within-the carriage. A gear 76 on shaft 72mesh'es with a gear 77 on shaft 7 3 so that these shafts rotate at the same speed inopposite-directions. Gear 77 is driven bya gear 78 fixed to a shaft '79,

whichin turnis drivenfrom the main drive" shaft 42 through gears 80 "and'81.- It will be noted that the fa'ceof gear 81 is of such width as to maintain contact with the gear 80, as the same is advancedv and retracted with the lengthwise advance and retraction of the tool carriage toward andfrom the work.

The crank shafts 7 Qand 73 are thus operated continuously sothat the'carrier plate 62 is reciprocated continuously and thetool 17 carried thereby-passes back and forth through the work. Each down stroke of the tool isa cutting stroke and each upstroke an ldle or return stroke. Thev tool carriage 53 is" given two distinct motions. It is reciprocated toward and from the workin timed relationwith the strokes of the tool, so as to efl'ectcutting engagement with'the tool and ,workon' each down'stroke' and to'provide clearance between the tool and work during each upward stroke it is alsofed slowly towardthe work as the cut progresses, until a slot of desired depth has been formed, and then quickly returned to the initial feed position. Although this dual movement may be accomplished in various ways an extremely simple compact mechanism for the purpose will now be described.

i This mechanism includes a lever 82 extending transversely of and within the tool carriage 53. This lever is mounted at one end upon a horizontal pivot 83, in a bracket 84 fixed to one wall of the housing, the other end thereof carrying a shoe 85 guided within a bracket 86 fixed to the opposite wall of the carriage. A roller 87, journalled in the lever, rests upon a cam 88fixed to the crank shaft 73. The cam 88 is so shaped asto raise and lower the lever at the beginning and end of each down stroke of the tool 17. A bar89 is mounted for vertical reciprocation in a guideway 90 formed in the front face of the rail 75 carried by the carriage. A second roller 91 journalled in the lever 82 bears beneath an element 92 projecting laterally from the bar 89, through which the bar is raised and lowered with the lever. A wedge-shaped portion 93 at the upper end of the bar engages between a roller 94 carried by abracket 95 depending from the top of the tool carriage, and a roller 96 journalled in the forward end of bar 97 The arrangement is such that when the bar 89 and wedge portion 93 thereof have been elevated by the lever 82 into the full line position of Figure 1, roller 94 is forced away from roller 96, causing a corresponding movement of the too-l carriage toward the left, and when the bar 89 is lowered so as to lower the wedge portion 93 into the dotted line position of this figure, roller 94 approaches roller 96, with a corresponding movement of the tool carriage toward the right. The tool carriage is thus reciprocated continuously toward and from the work intimed relation with the vertical reciprocation of the tool.

The mechanism for feeding the tool carriage toward the work as the cutting progresses is also actuated by the lever 82. In this instance this mechanism includes a feed cam 98 fixed to a shaft 99 journalled in spaced parallel arms 100, constituting the side members of'a frame supported by a casting 101 fixed upon the rear portion of the upright side members 55. An upright lever 102, fixed intermediate its ends upon a rock shaft 103, journalled in the arms 100, is provided at its lower end with a nose 104, which bears against the cam, and at its upper end is provided with a nose 105, which bears against the rear end of the bar 97 The bar 97' is mounted for lengthwise movement in the fixed bar 59, hereinabove mentioned, supported by the upright side member 55. A lever 106, fixed to one end of a rock shaft 107 journalled in the forward ends of the arms 100, carries a roller 108 which bears upon the lever 82. An appropriate spring 109, surrounding the shaft 107, maintains a downward yielding pressure on the lever 106 so as to maintain the roller 108 against the lever 82. An arm 110 fixed to the other end of the rock shaft 107 carries a pawl 111', which engages appropriate teeth on a ratchet wheel 112. A stop pawl 113, supported loosely on the shaft 103, prevents rotation of the ratchet wheel 112 except in a counterclockwise direction (Fig.1). The ratchet wheel 112 is mounted loosely on the shaft 99 and is connected in driving relation therewith through a clutch 114. The arrangement is such that upon each up stroke of the lever 82, the lever 106, shaft 107 and arm 110 are swun clockwise, and the pawl 111 rotates the ratchet wheel 112 through a predetermined angle counter-clockwise and when the clutch 114 is closed, this rotation of the ratchet wheel is transmitted to the cam 98; and upon each down stroke of the lever 82,-the arm 110 and pawl 111 perform an idle stroke, the ratchet wheel being held against rotation by pawl 113. When the clutch 114 is closed, the cam 98 is thus slowly driven intermittently in a counter-clockwise direction as indicated by the arrow in Figure 1.

The cam98 is of the snail type having a gradually increasingradius and an abrupt shoulder 115. As the cam rotates the lever 102 is rocked counter-clockwise, and thebar 97 is advanced toward the left. This movement of the bar 97, transmitted through the roller 96, wedge portion 93 and roller 94, causes a corresponding feed movement of the tool carriage toward the work. This movement continues until the nose 104 on the lever 102 passes over the shoulder 115on the cam, at which time tool carriage is free to return to itsinitial'feed position.

The return movement of the tool carriage toward the right (Fig. 1) is accomplished, in the machineshown, by a pair of springs 116, within the casting 101. Each spring surrounds a tension rod 117, extending rearwardly from the tool carriage into the casting 101, and is interposed between a nut 118 on the rod and a web 119 in the casting.

The indexing mechanism, including shaft 25 and the parts driven thereby, is thrown into operation automatically, to rotate the work through a predetermined angle, after the completion of each slot. In the machine shown the mechanism for this purpose is placed under the control of the upright lever 102. This mechanism includes an arm 120, fixed to the rock shaft 103 so as to swing with lever 102, and connected at its lower end to a horizontal rod 121, mounted for lengthwise movement, through a boss 122 carried by a bracket 123, fixed to the web 60. A block 124, adjustably fixed to the rod 121, carries a pivot pin 125, supporting urcs 1 and 6,,by aspring127 resti one end ofa lever 126, so that the lever 126 travels lengthwise with the rod 121. The lever .126 is yieldably snpportedin the horizontal positionshown in full .lines in Fig 0 fixed to the upper end of a lever 131. Lever 131 is mounted intermediate its ends upon a horizontalpivot pin 132 fixed in the bracket 123, and at its lower end carries a set screw 133 which limits the clockwise swing thereof.

A set screw 134, adjustably fixed in a boss 135, carried by the upper end of lever 131, is aligned with a rod 136 fitted for "ertical movement within a bore 137 in a valve block 138 carried by the bracket 123. The lower reduced end 139 of the rod 136 abuts the end of a valve stem 140 projecting upwardly from a valve 141, disposed in a chamber 142, and cooperating with a seat 143 at the lower end of the bore 137. The chamber 142 is open to an appropriate fluid pressure source (not shown) through a pipe 144. A spring 145 tends at all times to lift the valve 141 toward its closed position against the seat 143, but permits the valve to be lowered away from the seatunder the downward thrust of the rod 136. An exhaust port 146, leading from the bore 137, is covered by the rod 136 when the rod is in the lower position of Figure 6, but when this rod is elevated to close the valve 141, port 146 is uncovered,

and bore 137 is then open to the atmosphere.

A port 147 maintains communication be tween the bore 137 and a pipe 148 leading to the upper end of a cylinder 149, supported by a fixed bracket 150. A piston 151, within the cylinder 149, is connected through a rod 152, with one arm 153 of a bellcrank lever, rockably supported upon a fixed pivot 154. The other arm 155 of the lever is operatively connected ,to the detent bar 50, so that when piston 151 is depressed by fluid pressure ap plied through pipe 148, the bar is with drawn from engagement beneath the shoulder 49 on the stop cam 48. A rod 156, sup- 50 ported by the lever 126 and extending downwardly through the spring 127, is provided at its lower end with a slot 157, for receiving a pin 158 carried by the horizontal arm 153 of the bell-crank lever. The arrangement is such that when this arm 153 is depressed by the piston 151, the pin 158 strikes the lower end of slot 157, so as to pull the rod 156 downwardly, and depress the lever 126 into the dotted line position of Figure 6. In this depressed position the plate 129 is lowered below the plane of plate 130.

The control mechanism ust described thus operates as follows: As the lever 102 swings counter-clockwise under the action of the cam 98, to feed the tool carriage 53 toward the work, the arm 120 swings with this lever, so as to force the rod 121 and thelever 126 toward'the right (Fig. 1) This movement continues until the nose 104 on lever. 102

chamber 142 is admitted through bore 137,

port 147, and pipe 148 to the cylinder 149 to depress the piston 151, and arm 153 of the bell-crank lever and thus withdraw the bar 50 in the manner just described. This action of the bell-crank lever is transmitted through the rod 156 to the lever 126, so that the plate 129'is lowered out of engagement with the plate 130, and the lever 131 is free to rock clockwise permitting the roc 136 to rise and the valve 141 to close. Port 146 is thus opened to port 147 and the fluid in cylinder 149 is free to escape. This permits the bar 50 to be again advanced against the cam 48 under the pressure of the spring 52.

The instant that the bar 50 is withdrawn from engagement with the shoulder 49 on the cam 48, the cam and shaft 25 start rotating under the action of the fr ction clutch, hereinabove described, and continue to rotate until the shoulder 49 again strikes the bar 50, which has in the meantime been returnel into position against the cam in the mannerjust described. 1 The shaft 25 thus rotates through exactly three hundred and sixty degrees and then comes to rest.

In the machine shown the feed cam 98 remains at rest during each rotation of the shaft 25, and for this purpose the clutch 114 is placed under the control of shaft 25. As shown in Figure 5 the clutch is controlled by the upright forked arm 160 of a bell-crank lever, mounted upon a pivot pin 161, fixed in a bracket 162. The other arm of this lever is connected through a pin 163 with a vertical rod 164, connected at its lower end to a bar 165. Bar 165 is mounted for lengthwise movement in a fixed guide 166 and carries a roller 167 at its lower end. T'he roller 167 rests upon a cam 168 fixed to the shaft 25. The cam 168 is of circular form except for a recess 169 in the periphery thereof. The rod 164 extends through the web 60, and a spring 170 on the rod, between the web and a collar 171 fixed to the rod, maintains the roller 167 against the cam 168. lVhen the shaft 25 is at rest with the shoulder 49 of cam 48 against the bar 50, the roller 167 is seated in the recess 169 of the cam 168 and the clutch 114 is closed, so that the feed cam 98 rotates with the ratchet wheel 112. As soon as shaft 25 rotates,however, the roller 167 rises out of the recess 169, so that the bar 165 and rod 164 are elevated and thebell crank is rocked counter-clockwise (Figfi'5) so as to open the clutch 114 and the feed cam 98 comes to rest. The clutch 114 remains open until the shaft 25 has completed one revolution and returned the recess 169 beneath the roller. 167 so as to permit the .rod 164 and bar. 165 to be again lowered into the position of Figure 5.

As hereinabove mentioned the tool 17 is reciprocated along two. distinct paths alternately, when following-one pathit forms one wall of the slot, in the work and when following theother path it forms the other wall of the slot. Mechanism for producing this peculiar motion is shown in Figures 1, 2, 3 and 7 to 9. The tool carrier plate 62 carries two spaced studs 172 and 17 3 fixed therein and extending rearwardly therefrom. These studs carry rollers 174and 175 and shoes 176 and 177, respectively. Each shoe 17 6- 177 has a curved surface 178-179 adapted to bear against a correspondingly shaped surface 180'181, on acam block 182183. Blocks 182 and 183 are supported on. studs 184 and 185, extending through the opposite side walls of the tool carriage 53. Vertically adjustable wedges 186 and .187 are interposed between the blocks 182and 183 and are supported by rods 188 and 189, extending upwardly through the top of the carriage 53, and carrying nuts 190 and 191 on the upper ends thereof. By turning the nuts-190' and 191 the wedges 186 and 187 may be raised or lowered to thereby adjust the cam blocks 182 and 183 toward or from the shoes 176 and 177.

A cam block 192, interposed between the rollers 174.and 17 5, is provided at opposite sides with curved surfaces 193 and 194, which extend substantially parallel with the curved surfaces. 180 and 181, respeotively.- The block 192 is mounted upon the front face of a horizontal slide plate 195, and is formed with a horizontal groove 196 for receiving a horizontal guide rib 197 on the slide plate. The front wall 74 of the tool carriage 53 is cut away as at 198 to form a horizontal guideway for the block 192 and plate 195, the block and plate being retained therein by appropriate plates 199. Both the plate and block are movable horizontally within the guideway 198 and the block is movable horizontally across the face of the plate. Bosses 200 at the upper and lower ends of the block-192 are interposed between spaced bosses 201 formed at the upper and lower ends of the plate 195, and compression springs202 and 203 between these bosses serve to yieldably retain the block centrally disposed on the face of the plate.

The plate 195 is reciprocated horizontally by a cam 204 disposed between rollers .205 and 206 journalled within the plate. The cam 204 is fixed to a horizontal shaft 207 driven by a gear 208 fixed thereto; The gear 208 is driven from a' gear 209 onthe crank shaft 73, through a gear 210, supported by .a bracket 211 fixed to the front wall 74 of upper endiof'their stroke and the cam 204 is in its upper dead center position, so that the horizontal slide plate 195 and cam block 192 are in central position. In this position the rollers 174 and 175 contact with the surfaces 193 and 194 on the cam .blockand both shoes 176 and 177 are withdrawn from the surfaces'180 and 181 on the cam blocks 182 and .183. As the cam 204 rotates counterclockwise from this position the plate 195 is-shifted toward the left, "and the springs 203force the cam block 192 toward the left,

so that the shoe 176 is forced against and held in'contact with the surface 180.v This lateral movement of the shoe 17 6is transmitted through the stud 172 tothe carrier plate 62 so that the tool 17 is shifted towardthe left. .Atthe sametimethe carrier plate 62 and tool are traveling down under the action of the crank shafts 72 and 73 and links 66 and 67, so that the shoe 176 follows the SllI'fZLCBllSO, and causes thetool to follow a path such as indicated by the line 6 in Figure 8. This down stroke continues until the .,parts arrive at the position shown inthis figure, the cam 204' having arrived at its left ninety degree positionand the crank shafts 72 and 73 having turned through one hundred and eighty degrees .in lower dead centerposition. On the upward return stroke of the carrier plate 62 and tool the cam 204' maintains the shoe in contact with surface 180 until the tool approaches the upper limit of its stroke, and the cam 204 approaches its lower dead center position.

Onthe next downward stroke the cam 204 continues to rotate counter-clockwise, shifting the slide plate 195 toward the right and causing the springs 202 to shift the cam block 192 toward the right, to thereby shift the shoe177 into contact withsurface 181. The

,carrier plate 62 and tool 17 are thus shifted toward the right, and the shoe 177 in, following the surface 181 causes the tool to follow along the path 6 of Figure 9. Figure 9 illustrates the positions of the parts at the lower end of the second down stroke of the tool. It is noted that the cam 204 has reached its right extreme position and that the crank shafts are again in lower dead center position. Upon the following up stroke the shoe 177 continues to follow the surface 181 until .the cam 204'approaches its upper dead center position. 9

The camblock 182 thus determines the "path of travel of. the tool duringone recipro- "cation and the, cam block 183 determines the path'of travel. of the tool during the next reciprocation; By raising or; lowering the i-wedges 186 and 187 these blocks may be adjusted toward and from each other to there- :byivarythe width of the slot cut by the tools. "Various; changes may bemade-tinithe em bodiment'of the invention hereinabove described without departing from or sacrific- 2 "alternately during alternate reciprocations c -Is thereon-and means for'effe'cting a relative feed movement between the tool and-work. "2. In a" slotting'ma'chine the combination ofa tool holder, tool reciprocating means, tool shifting means reciprocatingintimed relation with said reciprocating means to cause the tool'to follow two different cutting paths alternately'during alternate reciprocati on thereof, means forld'eterminin'gthe shape of said paths, and'means for-effectinga relative feedmovement between the tool and work. 7 V

;3. In a slot-tingmachine thecombination of a tool holder, tool reciprocating means, means reciprocating in' timed relation" with 's'aid-reciprocating-means to cause the tool to follow two different cuttingpaths alternately du-ring alternate reciprocations thereof, means fon -determining the shape of .7 said paths, means for adjusting said last named means to vary said paths, and means for eifec ting a relative feed motion between the tooland work.

P4. In a' machinefor"forming; slots with non parall'elwallsthe combination of a tool, means for reciprocatingsaidtool along two 'reversely' curved'path s' alternately during alternate:reciprocations'fthereof to form the opposite walls 'of' a' slot, andmeans for: adjust-ing said means tomodify thepaths of 'travel'of said tool to thereby modify the slot. 1 5. In a slottin'g'machine the combination as afl'tool carrier, means for reciprocating "said carrier, means providing two guide surfaces, and means automatically operable to shift said carrier intocoacting relation with said surfaces,v alternately, to thereby cause -said carrierto reciprocate along either of two :pa h I r In a slotting machine the combination ofjai-toot carrier, meansfor "reciprocating 'said carrier, meansproviding two: guide sur faces imeans onsaid "carrier for engaging said surfaces, and means for shifting said "C5 carrier to effe ct and maintain contact of said rrgszagazo engagingmeans' with: either of said? surfaces,

selectively.

1 7LIn a machine 'tool'or. theilike the combination of a frame, a tool carriage movable thereon toward and from the work, tool reciprocating -means on said carriage, feed mechanism supported by said frame for feeding said carriage toward and from the work,

and mechanism on said'carriage coacting with said feed mechanism to effect reciprocation of said carriage toward and from the work in rmentmovable'in timed relationwith said tool ireclprocatlng means for' reciprocating said carriage toward and from the'work.

means on said carriage, feed mechanism" for advancing said carriage intermittently toward. the work intimed relation with said '95 :tool' reciprocating means, and .meansfor reciprocating said carriage toward and from the work in timed relation with said tool reciprocating means. i

1 10. In aimachine tool or the like the com;

bination of a tool carriage, tool reciprocating "means thereon feed mechanism for advanciing said carriage toward'the work at a'pre- 'determin'ed rate, mechanism for reciprocat- In a machine tool or the like the com- "b1nat1on:of: a tool carriageytool re'clprocating ing saidcarriage toward and from the work,

: and an element driven by said tool reciprocat ing means "for actuating both ofsaid mechanisms.

' 11. In a machine tool or the like the commeans on said carriage, and means for intermittently advancing said carriage toward the work in timed relation with said" tool reciprocating 'me'ans, said advancing 'means including a'reciprocating wedge carried'by said carriage and operable to cheat retraction ofsaid'carriage before each return stroke of saidrtoo l reciprocating means.

12.) In a'machine tool or the like the-combination of a' work support, indexing 1nech- 'an1sm,-a tool carragega' tool reciprocating means on said carriage, mechanism for feeding Sflld' carrlage toward and from the work,

means for reciprocating said carriage toward and from the work in timed relation with saidi-to ol reciprocating means, and means controlled by said feed mechanism for controlling saidindexing mechanism.

13. In a machine tool or the like the com- "bination of a work support, indexing mechan'lsm ia tool carriage, tool reciprocating binationof atool carriage, tool reciprocating means on said carriage, mechanism for feeding said carriage toward and from the work, trip mechanism coacting with said feed mechanism and operable during the return feed of said carriage to render said indexing mechanism active, and means for reciprocating sai'd carriage toward and from the work in timed relation wtih said tool reciprocating means.

14. In a machine tool or the like the combination of a tool carrier, means for reciproeating said carrier, means providing two guide surfaces, means on said carrier for coaction with said surfaces to guide said carrier, and means automatically operable to shift said carrier into coacting relation with said surfaces alternately to thereby vary the path of travel of the tool for alternate reciprocations thereof.

15. In a machine tool or the like the combination of a reciprocating tool carrier, means providing two guide surfaces, two shoes carried by said carrier for coaction with said surfaces respectively, and means automatically operable to shift said shoes into coacting relation with their respective guide surfaces alternately to thereby vary the path of travel of the tool for alternate reciprocations thereof.

16. In a machine tool or the like the combination of a reciprocating tool carrier, means providing two curved guide surfaces, a shoe rockably connected with said carrier for coaction with each surface to determine the path of travel of the tool, and means for automatically shifting" said shoes into coacting relation with their respective guide surfaces alternately to thereby vary the path of travel of the tool for alternate reciprocations thereof.

17. In a machine tool or the like the combination of a reciprocating tool carrier, means providing two curved guide surfaces, a shoe on said carrier for coaction with each surface, and resilient means for automatically shifting and maintaining said shoes in coacting relation with their respective guide surfaces alternately to thereby vary the path of travel of said carrier and tool for alternate reciprocations thereof.

18. In a machine tool or the like the combi' nation of a reciprocating tool carrier, a pair of members each providing a guide surface for said carrier, means on said carrier for coaction with said surfaces selectively, means for automatically shifting said carrier to efl'ect a coacting relation between said means I and each of said guide surfaces alternately to thereby effect operation of the tool along diiferent paths for alternate reciprocations thereof, and means for eflecting a relative adjustment between said members to thereby vary the relation between the paths.

19. In a slot forming machine the combination of a tool holder, means for reciprocating said holder to eifect alternate cutting and idle return strokes, means for shifting said holder between successive cuttins strokes, and separate non-parallel guides ior said holder 00- operating with said shifting means and alternately effective to determine the course of I travel of said tool holder during successive cutting strokes.

20. In a slottingmachine the combination of a tool holder, means for reciprocating said holder to eifect alternate cutting and idle reguides for said 

